It is a paraphrase of the Veni Sancte Spiritus, a Latin hymn that is traditionally sung during Pentecost. The book is a poetic and spiritual interpretation of the hymn, which is a prayer asking for the Holy Spirit to come and fill the hearts of believers with grace and power. Johnson's paraphrase is intended to be a devotional aid for Christians who wish to deepen their understanding of the Holy Spirit and its role in their lives.